Method and mechanism for folding paper boxes



Dec. 5, 1950 E. G. STAUDE METHOD AND MECHANISM FOR FOLDING PAPER BOXES 5 Sheets-Sheet 1 Filed Dec. 28, 1946 vard/.- Q-Proms Dec- 5, 1950 E. G. STAUDE 2,532,522

METHOD AND MECHANISM FOR FOLDING PAPER BOXES 5 Sheets-Sheet 2 Filed Dec. 28, 1946 6dwin Q. Sfotude (Z7 M, 62%;,MM o-4" Dec. 5, 1950 E. G. STAUDE METHOD AND MECHANISM FOR FOLDING PAPER BOXES 5 Sheets-Sheet 5 Filed Dec. 28, 1946 OVEN-TOW dwin G. Staude 6, 1 W a [5 gfiw-rogsgd" E. 'G. STAUDE METHOD AND MECHANISM FOR FOLDING PAPER BOXES 5 Sheets-Sheet 4 Dec. 5, 1950 Filed Dec. 28, 1946 ling- WM cSdwin G. stoude E. G. STAUDE 2,532,522 I 5 Sheets-Sheet 5 Dec. 5, 1950 METHOD AND MECHANISM FOR FOLDING PAPER BOXES Filed Dec 28, 1946 Patented Dec. 5, 1950 2 53 52 METHOD AND MECHANISM FORFOLDING PAPER BOXES Edwin G. Staude, .Minneapolis, Minn.,assignor to The Sperry Corporation, New York, N. 12, a corporation of Delaware Application December 28, 1946, Serial No. 718,941

9 Claims.

1 The present invention pertains to a method and mechanism for folding paper box blanks into the form-of knocked down boxes. More particularly, it has to do with the infolding (as distinguished from outfolding) of such box blanks.

The present invention may be employed in the infolding of a variety of types or forms of box blanks all of which have in common the feature that they embody an opposed pair of side panels which are to be infolded as well as at least one additional panel along one of the remaining pair of edges of the blank and which likewise must be infolded, such additional panel having at its ends a pair of tabs articulated thereto along diagonal crease lines. Those familiar with the art of making knocked down paper boxes will readily appreciate the large number of forms of box blanks to which the structural features so far outlined are common. Originally most such boxes were folded and glued in so-called Brightw-ood type machines, in which the box was folded and glued in erected form about a plunger, the box so formed being subsequently collapsed by hand for shipment. Gradually machines were perfected which made it possible to fold at least certain of such boxes in knocked down form, in some cases by outfolding and in other instances by infolding. Versatility of such machines has increas d, making possible the folding in knocked down form of an increasing number of the available types of boxes in the general class described above. One of the latest forms of such machines is disclosed in my Patent No. 2,291,063 issued July 28, 1942.

Some few boxes of the general class of panel arrangement outlined above have, however, been impossible to fold in even so versatile a machine as that of my Patent No. 2,291,053. An example is the box of Patent No. 644,857 issued on March 6, 1900 to Robert Gair. Although the latter patent is long since expired and the box which it discloses thus free for general use, its employment has been circumscribed by the necessity of making it with the costly type of operation inherent in a Brightwood type of machine, and use of such boxes has therefore been limited despite the special qualifications of the box for certain purposes as, for example, in packaging tomatoes.

The factor which has precluded folding the box of Patent No. 644,857 111 knocked down form on available machines is that it has tabs articulated on diagonal crease lines on adjacent side panels (lying at rightangles to each other) and which must be reversely folded when infolding the blank to knocked down form. Not only are there, as noted above, a pair of opposed side panels to be infolded as well as an additional side panel to be likewise infolded and having tabs on its ends, but'in addition there are tabs articulated to such opposed panels, as well, along diagonal crease lines.

It is an object .of the present invention to provide a method and mechanism for infolding in knocked down form, and in a novel manner, boxes o'fxthe general styleo'f construction outlined above and including even such tricky special styles as the box of said Patent No; 64%;85'7.

Moreover, it is the object to accomplish the infolding in knocked down form of such boxes in a continuous and straight line operation so that production speed maybe at a maximum.

A further object of the invention is to provide-a mechanism in the form of an attachment applicable to machines of the form shown in my prior Patent No. 2,291,063 referred to above and by means of which such machine may be adapted for the 'infolding of boxes like that of Patent No. 644,857, in which tabs on diagonal crease lines on adjacent'side panels may be reversed or folded back-onto the exterior-0f the infolded side panels.

Further objects and advantages of the invention will become apparent :as the following description proceeds taken in connection with the accompanying drawings, in which:

Fig. l is a side elevation of a folding attachment embodying the present invention, the same being shown as installed in the second section of a folding and gluing machine of the form disclosed in my prior Patent No. 2,291,053;

Fig. la a transverse sectional view taken substantially along the line lw-Ia in Fig. '1;

Fig. 2 is an enlarged fragmentary perspective view of the attachment shown in Fig. 1 and illustrating the progression of box blanks through the same;

Fig. 3 is an enlarged fragmentary detail perspective view showing a partially folded condition for the flaps at the leading left-hand corner of one of the blanks as it progresses through the mechanismof Fig. 2.;

Fig. 4 is a'generally schematic perspective view indicating the progress of the blanks through that section of the machine which follows the section appearing in Figs. '1 and 2;

Figs. 5 and 6 are, respectively, fragmentary side elevation and plan views of one of the sets of taken substantially along the line 'll in Fig. 5; and

Figs. 8, 9 and are vertical sectional views taken, respectively, substantially along the lines 8-8, @9 and l8ill in Fig. 6.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications, alternative constructions and methods falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawings, I have shown in Fig. 1 an attachment, designated generally as 55, installed in the second section of the machine of my prior Patent No. 2,291,063. It is only in that section that alteration need be made to fod boxes in accordance with the present invention and consequently details of the re" mainder of the machine have not been shown, reference to my prior patent being possible for such information if desired. The attachment i5 is a preferred form of mechanism embodying my present invention and for carrying out my novel method of box folding herein disclosed.

Generally stated, the basic procedure which I employ in my novel method of folding is to make a preliminary, but only partial, infold of a pair of opposed side panels on the blank so that they project upwardly and inwardly over the body of the blank. Then an additional side panel, or panels, with tabs on diagonal creases is infolded, the tabs being swept back or reversed by the partially infolded pair of panels and as an incident to the infolding of such additional side panel. Thereafter infolding of the previously partially infolded pair of panels is completed.

' To that basic procedure I also contemplate, in

accordance with another aspect of my invention, adding, when desired, a coordinated folding of glue flaps articulated to the heretofore mentioned tabs. Not only is folding of such glue flaps accomplished at the proper time, but, more important, in a manner to aid in initiating the sweep-back of the tabs themselves along their diagonal crease lines. This sweep-back action is, in such case, initiated by striking of the tabs against part ally infoded flaps and is thereafter carried on by under-riding the tabs with reference to the partially infolded panels as outlined above in the basic procedure.

Such folding procedure will be better apprehended by reference to its application to a particular box blank. In Fig. 2 the blanks B are those for the box of Gair Patent No. 644,857 referred to previously. Such blank is cut and creased to define a main body panel a (see flat blank in Fig. 2 ready to enter the folding mechanism) with a pair of opposed side panels I) at its opposite ends and additional side panels 0 and d along the remaining edges. Joined to the side panel d is a cover c with a tuck flap 1. Diagonal crease or score lines I 6 divide the tabs 9 from the side panel c, such tabs having glue flaps h articulated to them. Moreover, diagonal crease lines I! divide the end panels I) to define tabs 1 on the same. Glue flaps y are provided at opposite ends of the panel d.

To infold the blank B in knocked down condition the following folding operations are sequentially performed in the machine section illustrated in Fig. 2:

(1) The leading and trailing panels b, b are partially infolded to overlie the body panel a in upwardly and inwardly inclined, raised position; coincidentally with such infolding of the end panels b, b, the tabs 2', z thereon are reversed with reference to the respective panels to which they are attached; and also coincidentally, the glue flaps it, h are partially infolded. (See the central one of the three blanks B shown in Fig. 2 for the position of the several blank elements at this point in the cycle.)

(2) The side panel 0 is infolded, engagement of the glue flaps h, h by folding fingers which have partially infolded the same serving to hold back the tabs g, 9 so that the latter begin to bend back on their diagonal crease lines H3, and such reversing of the tabs 9, g being carried further by their underriding contact with the partially infolded panels I), I) (see Fig. 3).

(3) The infolding of the pair of panels I), b is completed, flattening the underlying tabs 9, g down on the outside of the side panel c and causing adherence between glue spotted on the panels 22, b and coacting glue flaps h, h.

Provision is made in the illustrated machine for carrying out such sequential, timed folded operations while the blanks B are in continuous endwise motion. For that purpose a plurality of sets of traveling, swinging-finger folding units are provided, one set for each blank. Eight such sets appear in Fig. 1, each set including a leading folding unit a trailing foldin' unit I9 and a side folding unit 28 (see also Fig. 2). The corresponding folding units in each set are identical and accordingly a description of those for one set will suffice for all.

Bodily conveyance of the folding units E8 to 25 in unison with the traveling blanks is accom plished by endless roller chains 2!, 22 and 23 (see Figs. 2 and 6). These chains are trained over respective pairs of sprockets Z ta to 0, 25a to 0 (Figs. 1a and 2). Loose hubs 2?, 28, 29 and a disk 33 are interleaved with the three sprockets Zia to 240, the two outer sprockets 25a and Etc of this group being loose on the hub 29 and the central sprocket 24b being pinned to such hub and to the disk 3%. Upon tightening cap screws 3i all three of the sprockets 24a to 240 are clamped together with the hubs to form a solid unit, relative angular adjustment of the sprockets to vary the timing of the mechanism being made possible by loosening of the cap screws. A key 32 passing through the hubs 21, 28 and 29 serves as a slidable drive connection with the drive shaft 23, driven from the main drive mechanism of the machine (not shown).

The hubs 28, Si; are journaled in bearings carried by respective ones of a pair of spaced, platelike frame members 33 (Fig. 1a). Such frame members 33 are in turn bolted to, and project ou ward from the left end of, a central frame or body casting 34 of the attachment Hi. This frame 3 is slidably supported for adjustment transversely of the machine on a pair of guide rods 35 by manually operable adjusting screws 35 (see also Fig. 1). Lateral adjustment of the frame 3 3 is utilized in accommodating blanks of different widths.

At the opposite or right-hand end of the attachment l5 (Figs. 1 and la) provision is made for mounting the sprockets 25a to 250 in such manner as to facilitate tensioning of the individual carrier chains trained over them. The central sprocket 25b in that group is journaled on eccentric 3? having a sleeve extension 3'ia removably rp'inned to a disk .38. The sprocket' a is, somewhat similarly, journaled on an eccentric 39 having 'an end flange 38a. Cap screws it pass through arcuate slots in both the dish-38 and flange 39a, bging threadedin the adjacent or front one of a pair of frame extension plates M. A shaft 12., havinga retaining nut li'la on its outer end and an enlargement izb :on its inner portion, passes through the sleeve Sla. The far or rear end of the shaft 12 is :journaled in the :rear frame extension H while the third sprocket 250 is journaled on the enlargement 42b.

The frame extensions 4:! areslotted longitudh nally to receive bolts d3 (Fig. lat) which secure the same to the central frame 34. Upon loosening the bolts 33 the pair of frame extensions l'l together with the set oi spr-ockets 25a. to aZEcma-y be shifted bodily under the thrust or adjusting screws M (Fig. 1) which are mounted in threaded engagement with tapped holes in the central iramefi. it is by such shift that tension is adjustedsin the :chain 23 trained over the sprocket 25c. Tension in the chains 2! and 22 trained over the sprockets 25a and 25b is adjusted individually by loosening the cap screws ll) and nut 42a, :and then turning the eccentrics 3i and 39, as requ-ired.

Each leading folding unit 1-18 (see Figs. 7, 'sand 9:) includes a sled or support '50 arranged with its side edges slidably received in grooves 55 do fined in a mir or opposed :guides 52 secured to a supporting bar "55. The latter bar spans, and is secured to, upstanding end portions of the central frame The sleds A are secured to extension links 58a interposed at appropriate intervals in the chain 22. Fixed to each such sled is a housing 53 having journaied in it a transverse rockshaft 5a with an operating or crank arm fixed to its outerend. On such arm is a cam follower roller 56 arranged to ride along an edge =ca-ni 5i. brackets -46 adjustable longitudinally of a sup- The latter cam is carried by porting rail M (Figs. 5 and 7.) This rail -is fixed to the bar '45. A torsion spring '58 serves to urge the rockshaft 54 to turn in a direction to retain the roller 555 "in contact with the cam 51. Fixed to the ro'ckshaft 54 is a toothed sector '59 meshing with apinion 5% on a second transverse roclrshaft 5 i, also iournaledrin the housing 53. Carried by this latter shaft 611 is :a pair of folding fingers 62, 63.

The cam 5! is suitably contoured so that as .oneof the leading folding units 1183 moves forward across the'upper side of the attachment Iii, in the direction of the arrows A in Fig. 2, the folding 'iingers 62, 63 will-be rocked inward (of the blank) in unison to infold the 'glue flap hand'leading side panel b, respectively, on the leading end of the blank. The finger 62 is o'iisetslightly forward or" the companion finger 16-3 for a purpose which later appear.

The rear or trailing folding units '19 are substantially identical with the leading folding units 18 described above except that they are of the opposite hand. Further detail of description is accordingly unnecessary, it being suflicient to note that the'trailing folding units 19 have pairs of swinging folding fingers -95, corresponding to the fingers -52, 63 and .arranged'with the fingers (it slightly offset forwardly of their companion fingers t5 (see Figs. 2, :5 and -6?). Moreover, the sleds of the trailing folding units id are connected to extension links in the chain 21 rather than in the chain 22 as was .theficase for the leading fielding units.

.in :Fig'. 2, the follower rollers til The side folding units 20 are also of the travebing, swinging-finger type, but in this case include a folding finger 6% (see Figs. 2, 6, 7 and 10) which swings transversely of the path of travel for the blank rather than fore-and-aft of the same, as was the case with the fingers-of the leading and trailing folding units. In the particular construc- "tion :shown ('see Figs. 7 :and 10), the side folding unit 253 includes a sled 6? having its side edges slidably received in the :grooves is! of the guides 52 and fixed to an extension link 63 interposed in the carrier chain 25. On the sled is a housing 69 having a rockshaft ill journalled in it-and carrying an arm ii bearing a cam follower roller 12 on its outer endin position to roll along an edge cam 7 -3. The latter cam is mounted by brackets Pisa '(Fig. 10') adjustably received on a rail '53?) secured to the bar iii and similar to the rail '56 but on the side of the bar opposite the rail 36. Fixed to the rockshaft is a toothed sector M "(Fig '7') meshing with the pinion iii fast on a :rockshaft "5-6 journal-led in "the housing so and ca rying the'swinging folding finger .35. Thusas the follower arm ii is raised and lowered in accordance with the contour of the cam the folding finger $5 is correspondingly rocked. A torsion spring l8 retains the roller 32 pressed against the cam. Desirably an elongated face plate *19 is attached to the active outer end of the folding finger st (see Figs. 5 and 6) so to apply rol'ding pressure throughout substantially the full length of the side panel c on which such finger acts.

Having in mind the fo'ui of folding units described above for my atta "sent 15, let us consider the progressive fol ng in such attachment of one of the blanks 3 'fed into the some '(see Fig. 2). Such blan'i: is fed end-wise, :in the direction-or the arrows A and in flat condition, into the attachment by a positively timed conveyor mechanism, here shown as including an endless roller chain so having suitably spaced feed lugs ei on it engaging the rear edges of successive blanks and pushing them into the attachment iii. For a "suitable mechanism for feeding blanksone by one frorn'astackontosuc'h .a conveyor chain reference may be made to my rprior Patent No. 2,291,663 reie"'"-d to above. It is also to be observed that glue has been spotted or imprinted at k on the end panels b by suitable mechanism such as the glue applying wheel 2 (Fig l) preparatory to entry or the blanks into the section of the machine containing the attachment it.

As the successive blanks 13 enter the attachment #5 they under-ride an overhead carrier, designated generally as $3 in 1, and-a hold down bar 84 -(see also Fig. 2). The bar 3% is located over and slightly inward oi the crease between the body panel a side panel 0 to keep the blank from rising. The overhead carrier 8-3 is of the *iain-i endless siriction belt type, suitable form 0 aich shown in detail in prior Patent No. 2,291,053. "The chain is timed to deliver a blank 33 to each successive set of folding units with the blank accurately centered longitudinally of the set or group of ."lolders. Any slight lack of longitudinal registry between the folding units and 12-9 and the blank received by them is tolerated *by slippage of the friction type overhead carrier with reference :to the blank.

As -the'b1ank moves along to p onoi' the central one of the 'thre'e l and trailing folding units I8, I9 are raised by the cam 51, rocking the pairs of fingers 52, 53 and 64, 65 inward of the blank. The glue tabs h, h and the side panels b, b, are thus partially infolded to the position shown and in which they project upwardly and inwardly over the plane of the main portion of the blank.

coincidentally with such infolding motion of the leading and trailing side panels I), b the tabs 2, i are wiped back over the exteriors of such panels by the action of a stationary hold down bar 65. As the blank under-rides this latter hold down bar the rising tabs 2' strike it and are thus held back so that they become reversely folded on the exteriors of the panels I) to which they are articulated along the diagonal crease lines H. The underside of the hold down bar 85 slopes downward toward the horizontal plane of the blanks from a somewhat elevated position at the central portion of the attachment l5. It should be noted in passing that the hold down bars as and 85 in effect overlap (Fig. 2) so that at least one of them is always effective to hold the blanks down in position. In order that the hold down bar 84 may be extended so far forward it is projected between the paths of the spaced pairs of folding fingers on the leading and trailing folding units i8 and 19.

A dwell of the leading and trailing folding units l8, !9 in their partially infolded condition described above is next accomplished, the cam 5'! having a suitable straight portion for that purpose. The other edge cam 13 is contoured so that during such dwell it operates on the roller 12 to rock the finger 66 of the side folder unit 223 inward. The latter finger thus folds inward the side panel to overlie the main body panel a beneath the partially infolded opposed pair of panels I) (see the last of the three blanks B in Fig. 2).

As an incident to the infolding of the side panel 0 the tabs g. g on it are reversed along their diagonal creased lines 5. Thus as the side panel c begins to fold inward the tabs g are held back by the pressure of the fingers 62, 64 on the partially infolded glue flaps h. Then as the infolding of the side panel 0 continues the tabs g, g are wiped back still further by pressure exerted from the partially infolded panels 19, b, the latter pressure being exerted through the flaps h, h in the present instance and directly if flaps like h, h are omitted in the blank. As to such action, it will be observed upon reference to Fig. 3 that the tabs g, g with their attached glue flaps h, h under-ride the partially infolded panels 17, b as the panel 0 is infolded. It is to prevent the corners of the glue flaps h from catching on the edges of the panels b as they under-ride the latter that the fingers 62, at are offset slightly forward of their companion fingers 63, 65 in the manner previously mentioned.

Upon completion of the infolding of the side panel 0 and reversal of its tabs g, g as described above, the infolding of the opposed pair of panels I), b is completed by a further inward swing of the fingers on the leading and trailing folding units i8, i9. This completes the folding in the attachment [5. Accordingly the cams 51 and 13 are shaped at their left ends to swing the folding fingers of the folder units l8 to 28 free of the folded blank, the folds accomplished being retained by the hold down bar 85 in coaction with additional hold down rods 36. It will thus be seen that as a result of the folding in the attachment I5 the side panel 0 is infolded with its tabs g reversed on its exterior and the glue flaps h reversed on such tabs. Moreover, the opposed pair of panels b are infolded with their tabs 2 reversed and the spots of glue is pressed down on the glue flaps h, causing adherence between the same. This completes the infolding and joining of the side walls around three sides of the bottom or body panel a of the box.

The remaining gluing and folding operations to complete the box may be accomplished in the following sections of the machine of my previously mentioned Patent No. 2,291,053, operating in their normal manner and hence require no detailing here. Suffice it to say that the blanks continue to move uninterruptedly in a straight line, the tabs 7' being infolded in the next machine section '8'! (schematically illustrated in Fig. 4) by leading and trailing traveling folding fingers 88, 39, the folds made in the attachment l5 being retained by a hold down bar 98. Following the section 3?, glue is applied to the tabs 7' by suitable means (not shown) and thereafter suitable sweeps (not shown) swing the side panel d and attached lid and tuck flap e, f inward to overlie the bottom panel a with glue adherence between tabs 2', i and flaps :1. Finally the completed blanks are received in the suitable stacker (not shown).

From the foregoing it will be perceived that a novel box folding method of wide utility has been afforded as well as a simple and reliable mechanism of wide versatility, that may be embodied in an attachment capable of easy installation in existing machines if desired.

I claim as my invention:

1. The method of infolding a box blank having a pair of opposed side panels and at least one additional side panel along a side of the blank lying at right angles to said pair and said additional panel having tabs on its ends articulated thereto along diagonal crease lines, said method comprising a preparatory inward turning of said opposed pair of panels into partially infolded position in which they are upwardly and inwardly inclined over the body portion of the blank, then infolding said additional panel against said body portion of the blank, while wiping said tabs rearward with reference to said additional panel by pressure on the same from the partially folded opposed panels, and completing the infolding of said opposed pair of panels to overlie the reversed tabs on said additional panel.

2. The method of infolding a box blank having first and second side panels articulated to the body of the blank along crease lines lying at right angles to each other and said first panel having a tab articulated thereto along a diagonal crease line located at the end of such panel adjacent the second panel, said method comprising partially infolding said second panel to overlie the blank body in upraised and inwardly inclined position with reference thereto, and subsequently infolding said first panel While simultaneously wiping said tab rearwardly of said first panel by under-riding said tab with reference to said second panel.

3. The method of infolding a box blank cut and creased to define a body panel bordered on two opposite sides by a pair of opposed side panels and along a third side by an additional side panel and with tabs articulated to said opposed panels by diagonal crease lines as well as a pair of tabs articulated to the ends of said additonal panel by diagonal crease lines, said method comprising moving said blank substantially continuously in ence to the partially infolded pair of panels, and

thereafter completing the infolding of the latter panels.

4. The method of infolding a box blank cut and creased to define a main body panel having a pair of opposed side panels thereon as well as an additional side panel extending between the first two, and in which tabs are provided at opposite ends of said additional side panel articulated thereto by diagonal crease lines, said method comprising moving said blank in a straight line path paralleling the crease line along which said additional side panel is articulated, making a preparatory partial infold of the leading and trailing opposed pair of side panels and retaining them for a dwell period in partially infolded condition in which they are upraised and inwardly inclined over the main body panel, during such dwell period infolding said additional side panel while wiping said tabs rearward thereof by under-riding the same with reference to said partially infolded pair of panels, and after substantial completion of the infolding of said additional panel completing the infolding of said opposed pair of panels to coincidentally complete the reversing of said tabs on the upper face of said additional panel, all without substantial interruption in the motion of said blank in said path.

5. In a mechanism for infolding a box blank having first and second side panels articulated to the body of the blank along crease lines lying at right angles to each other and said first panel having a tab articulated thereto along a crease line starting adjacent the intersection of the crease lines. between said side panels and said body and running diagonally outward along said first panel, the combination of movable first and second folding devices engageable respectively with said first and second panels, stationary cam means for moving said folding devices in timed r relation with each other to effect sequentially a partial infolding of said second panel followed by an infolding of said first panel with a rearward wiping of said tab by under-riding said second panel, and means for completing the infolding of said second panel.

6. In a mechanism for infolding a box blank cut and creased to define a main body panel having a pair of opposed side panels thereon as well as an additional side panel extending between the first two and in which tabs are provided at opposite ends of said additional side panel articulated thereto by diagonal crease lines, the combination of means for conveying said blank continuously in a straight line with said opposed pair of side panels at the leading and trailing ends of the blank, leading and trailing folder units and a side folder unit, means for moving all of said units bodily in unison with the travel of the blank by said conveying means, said leading and trailing units having fingers thereon swingable fore and aft of the blank and said side folder unit having a finger thereon swingable transversely of the blank, and means for actuating said several fingers in timed relation with each other to effect an infolding motion of the fingers on said leading and trailing units interrupted by a dwell in which such fingers are partially upraised over the blanks as well as an infolding motion of said finger on said side folder unit during such dwell.

7. In a mechanism for infolding box blanks, the combination of means for conveying a. blank substantially continuously in a straight line path,

a first pair of folder fingers arranged side-byside, means for moving said fingers bodily in unison with said blank conveying means while supporting said fingers to rock about a common axis fore and aft of the direction of bodily travel, one of said air of fingers having its active outer end offset slightly forward of the other finger of the pair, a third folder finger, means for moving said third finger bodily in unison with said blank conveying means while supporting such finger to rock transversely of the blank about an axis located at the side of the blank adjacent the forwardly offset one of said pair of fingers, and means for rocking all said fingers in timed relation with each other to effect an infolding motion of said pair of fingers interrupted by a dwell as well as to effect an infolding motion of said third finger during such dwell.

8. In a folding machine attachment of the general character described, the combination of a plurality of endless chains arranged side-byside and trained over corresponding sprockets arranged to revolve in unison, a plurality of sets of folding units, each unit comprising a carrier fixed to a corresponding one of said chains, one carrier in each set having a pair of folder fingers thereon arranged side-by-side to rock fore and aft of the path of carrier travel, one finger in each pair being offset slightly forward of the other, means including a stationary cam for rocking said pairs of fingers in unison and in timed relation with carrier travel, each unit also including a second carrier fixed to another of said chains and having a folder finger mounted thereon to rock transversely of the path of blank travel inward from the side of a blank adjacent said forwardly offset one of said pair of fingers, and means including a second stationary cam for rocking said folder finger on said second carrier in timed relation with carrier travel.

9. In a folding machine attachment of the general character described, the combination of a plurality of at least three endless chains arranged side-by-side and trained over correspond ing sprockets arranged to revolve in unison, a plurality of sets of folding units, each unit comprising a carrier fixed to a corresponding one of said chains, first and second carriers in each set having folder fingers thereon arranged to rock fore and aft of the path of carrier travel and a third carrier in each set having a folder finger thereon arranged to rock transversely of the path of carrier travel, and stationary cam means for rocking said fingers in timed relation with carrier travel.

EDWIN G. STAUDE.

REFERENCES CITED Country Date Great Britain -r Dec. 8, 193!) Number 

